Collagen-binding Microbial Surface Components Recognizing Adhesive Matrix Molecule (MSCRAMM) of Gram-positive Bacteria Inhibit Complement Activation via the Classical Pathway |
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| Authors: | Mingsong Kang Ya-Ping Ko Xiaowen Liang Caná L Ross Qing Liu Barbara E Murray Magnus H??k |
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| Institution: | From the ‡Center for Infectious and Inflammatory Disease, Institute of Biosciences and Technology, Texas A&M Health Science Center and ;the §Division of Infectious Disease, Department of Medicine, University of Texas Medical School, Houston, Texas 77030 |
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| Abstract: | Members of a family of collagen-binding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) from Gram-positive bacteria are established virulence factors in several infectious diseases models. Here, we report that these adhesins also can bind C1q and act as inhibitors of the classical complement pathway. Molecular analyses of Cna from Staphylococcus aureus suggested that this prototype MSCRAMM bound to the collagenous domain of C1q and interfered with the interactions of C1r with C1q. As a result, C1r2C1s2 was displaced from C1q, and the C1 complex was deactivated. This novel function of the Cna-like MSCRAMMs represents a potential immune evasion strategy that could be used by numerous Gram-positive pathogens. |
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| Keywords: | Collagen Complement System Host-Pathogen Interactions Microbial Pathogenesis Staphylococcus C1q MSCRAMM Classical Complement Pathway Collagen-binding Proteins |
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